Gizmos是场景视图里的一个可视化调试工具。

在做项目过程中。我们常常会用到它，比如：绘制一条射线等。

Unity3D 4.2版本号截至。眼下仅仅提供了绘制射线，线段，网格球体，实体球体，网格立方体，实体立方体，图标。GUI纹理，以及摄像机线框。

假设须要绘制一个圆环还须要自己写代码

using UnityEngine;using System;public class HeGizmosCircle : MonoBehaviour{ public Transform m_Transform; public float m_Radius = 1; // 圆环的半径 public float m_Theta = 0.1f; // 值越低圆环越平滑 public Color m_Color = Color.green; // 线框颜色 void Start() { if (m_Transform == null) { throw new Exception("Transform is NULL."); } } void OnDrawGizmos() { if (m_Transform == null) return; if (m_Theta < 0.0001f) m_Theta = 0.0001f; // 设置矩阵 Matrix4x4 defaultMatrix = Gizmos.matrix; Gizmos.matrix = m_Transform.localToWorldMatrix; // 设置颜色 Color defaultColor = Gizmos.color; Gizmos.color = m_Color; // 绘制圆环 Vector3 beginPoint = Vector3.zero; Vector3 firstPoint = Vector3.zero; for (float theta = 0; theta < 2 * Mathf.PI; theta += m_Theta) { float x = m_Radius * Mathf.Cos(theta); float z = m_Radius * Mathf.Sin(theta); Vector3 endPoint = new Vector3(x, 0, z); if (theta == 0) { firstPoint = endPoint; } else { Gizmos.DrawLine(beginPoint, endPoint); } beginPoint = endPoint; } // 绘制最后一条线段 Gizmos.DrawLine(firstPoint, beginPoint); // 恢复默认颜色 Gizmos.color = defaultColor; // 恢复默认矩阵 Gizmos.matrix = defaultMatrix; }}

把代码拖到一个GameObject上，关联该GameObject的Transform，然后就能够在Scene视图窗体里显示一个圆了。

通过调整Transform的Position。Rotation。Scale，来调整圆的位置，旋转，缩放。

补充：基于Unity3D使用LineRender组件绘制圆线

在此记录一下使用Unity3D 的LineRender绘制线的过程，经过测试LineRender与OpenGL的GL_LINE_STRIP绘制方式一样，因此计算完点之后需要把起始点即为终点，多算一个点才算闭合。

代码如下：

using System.Collections;using System.Collections.Generic;using UnityEngine;using UnityEngine.UI; public class DrawLines: MonoBehaviour{ public float m_radius = 1.0f; public Material m_material; public float m_lineWidth = 1.0f; private List<Vector3> vPath = new List<Vector3>(); // Start is called before the first frame update void Start() { int count = 60; for (int i=1; i<= (count+1); i++) { if(i == (count+1)) { float x = Mathf.Cos(2 * Mathf.PI / count) * m_radius; float y = transform.localPosition.y; float z = Mathf.Sin(2 * Mathf.PI / count) * m_radius; vPath.Add(new Vector3(x, y, z)); } else { float x = Mathf.Cos(2 * Mathf.PI / count * i) * m_radius; float y = transform.localPosition.y; float z = Mathf.Sin(2 * Mathf.PI / count * i) * m_radius; vPath.Add(new Vector3(x, y, z)); } } GameObject lineGroup = new GameObject("LineGroup"); GameObject lineObject = new GameObject("RadarLine"); LineRenderer line = lineObject.AddComponent<LineRenderer>(); line.material = m_material; line.useWorldSpace = false; line.positionCount = vPath.Count; line.startWidth = m_lineWidth; line.endWidth = m_lineWidth; line.SetPositions(vPath.ToArray()); } // Update is called once per frame void Update() { }}

运行一下看一下效果：

以上为个人经验，希望能给大家一个参考，也希望大家多多支持。如有错误或未考虑完全的地方，望不吝赐教。